Use-after-free in FreeBSD - CVE-2026-49412
Published: June 11, 2026
Vulnerability identifier: #VU134365
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-49412
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: FreeBSD Foundation
Affected software:
FreeBSD
FreeBSD
Detailed vulnerability description
The vulnerability allows a local user to escalate privileges.
The vulnerability exists due to use-after-free in the IPV6_MSFILTER socket option handler when copying the source-filter list from userspace. A local user can trigger concurrent operations to reuse a stale pointer to freed memory and escalate privileges.
The issue occurs in the IPv6 multicast subsystem while handling source-specific multicast filtering via setsockopt(2).
How to mitigate CVE-2026-49412
Install security update from vendor's website.